The subject matter disclosed herein relates generally to imaging systems, and more particularly to a method and system for performing attenuation correction of medical images.
Multi-modality imaging systems scan using different modalities, for example, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), and Single Photon Emission Computed Tomography (SPECT). During operation, image quality may be affected by various factors. One such factor is patient motion. Another factor is inaccurate attenuation correction between images acquired using two different imaging modalities caused by the patient motion.
Accordingly, at least one known PET-CT system utilizes data that is generated by the CT system to generate an attenuation correction of the PET scan data. Specifically, a plurality of emission attenuation correction factors are derived from CT data that is generated during a CT scan, wherein the CT system is specifically configured to generate data to be utilized for the CT attenuation correction factors. More specifically, the CT information is utilized to generate a linear attenuation map at 511 keV, which may then be applied to attenuation correct the PET information.
Moreover, at least one known PET-MR system utilizes data that is generated by the MR system to generate an attenuation correction of the PET scan data. However, utilizing the MR data to generate a linear attenuation map at 511 keV, which may then be applied to attenuation correct the PET information may result in unwanted artifacts or inaccurate PET quantitation and therefore may reduce the diagnostic value of images generated using the PET scan data.